[Plugin: Fast Secure Contact Form] Sends email with only subject "hi" to person who contac

This plug-in has been great and I love it. I only have one big problem with it.
I have no idea whats happening. Evey time someone uses the contact form to send me an email, they get an email back apparently from me only with subject “Hi” and nothing else. Anyone has any idea?
I just dont want to be seen as spammer or a weirdo!
Thank you in advance.